It is necessary for a detergent composition to have various functions such as powers to emulsify and solubilize stain components such as an oil, and detergency. A detergent composition for hard surfaces (e.g. a dishwashing agent to be routinely used by humans), a cleansing compositions for the body (e.g., a shampoo or body shampoo) and the like, among others, are required to keep improving the feeling upon use, such as rich foaming, no odor of a base material during use and adequate viscosity, as opposed to other detergents for industrial use. Meanwhile, a less yield of foaming is vital to detergent compositions for industrial use.
In order to enhance a foaming property and adjust a viscosity of a detergent composition, various thickening/foam-promoting agents have been developed, and fatty acid alkanol amides or amides are generally used as a thickening/foam-promoting agents. However, these nitrogen-containing compounds give rise to a change of hue or the like over time, depending on formulation conditions. Furthermore, a fatty acid diethanol amide raises concern about the possibility that its impure nitroso compound might be a cancer-causing substance. For these reasons, a thickening/foam-promoting agent free of nitrogen is desired.
Patent Document 1 discloses, as a thickening/foam-promoting agent free from nitrogen, a (poly)ethyleneglycol alkyl ether obtained by adding 1 to 3 moles of ethylene oxide to an alcohol having 8 to 12 carbon atoms used as a starting material. However, a short chain ethylene oxide adduct containing as few as about 1 to 3 moles of ethylene oxide contains a large amount (not less than 1% by weight) of unreacted alcohols. In addition, alcohols having 8 to 12 carbon atoms carry an strongly unpleasant odor. In particular, if unreacted alcohols having 8 to 10 carbon atoms are left behind in a large amount, the feeling upon use of such a detergent composition could weaken significantly.
While the alcohols may be removed by purification, the production process becomes complicated if the amount of the remaining alcohols is not less than several % by weight, which is industrially unfavorable in view of production cost. On the other hand, it is possible to decrease the amount of unreacted alcohols by increasing the number of ethylene oxide added, but addition of ethylene oxide in a large amount results in poor foaming.
As an example thereof, Patent Document 2 discloses an alkylene oxide adduct of an aliphatic alcohol which is improved in odor by introducing propylene oxide in addition to ethylene oxide. This adduct, however, has a low foaming property when included in a detergent composition, whereby failing to provide a detergent composition having a lower odor and a favorable foaming property.
Patent Document 3 discloses an alkylene oxide adduct of a higher aliphatic alcohol in which a short chain propylene oxide is introduced. However, the document focuses only on the application as an emulsifying agent or a solubilizing agent, and makes no reference to an odor and a foaming property.
Similarly, Patent Document 4 discloses as a detergent an alkylene oxide adduct of an aliphatic alcohol in which a short chain propylene oxide is introduced. However, the document gives no description to an odor and a foaming property.
Patent Documents 5 and 6 disclose a polyoxyalkylene alkyl or alkenyl ether in which a short chain propylene oxide is introduced as a detergent for industrial application. However, these documents make reference only to cleansing of oily matters and iron powder for industrial use, and give no description to an odor and a foaming property. Nor is there any mention about a dishwashing which requires an excellent foaming property, use for the skin or use for the hair.
None of the prior art documents describes the content of a raw material alcohol.
[Patent Document 1] JP-A-2004-277685
[Patent Document 2] JP-A-2003-226892
[Patent Document 3] JP-A-2004-98054
[Patent Document 4] JP-A-2002-226891
[Patent Document 5] JP-A-Hei06-316782
[Patent Document 6] JP-A-2003-13092